Creating EPS files from TikZ

Since tikz files are usually not accepted when submitting publications, it is necessary to create a standalone EPS or PDF file. That is, the tikzpicture should be embedded in a complete .tex file, which compiles into a correctly cropped picture, ready for inclusion with \includegraphics. The .tex file can be easily set up to mimic the environment of the main document, so that e.g. the fonts match.

Using the Preview Package

Option 1 is to use the preview package.

\documentclass[a4paper,10pt]{article}

\usepackage{tikz}
\usepackage[psfixbb,graphics,tightpage,active]{preview}

\PreviewEnvironment{tikzpicture}

\begin{document}

\begin{tikzpicture}
 % ...
\end{tikzpicture}

\end{document}

This works especially well when using pdflatex. It also works flawlessly with non-standard sizes, e.g. beamer slides or A0 posters. With "old" latex (producing DVI, which is then converted to postscript using dvips), this method has substantial problems. For one thing, all recent versions of TexLive have a bug in the postscript they produce. This can be fixed by replacing the line

\def\pgf@sys@postscript@header#1{\pgfutil@insertatbegincurrentpage{\special{!#1}}}

with

\def\pgf@sys@postscript@header#1{\AtBeginDvi{\special{! #1}}}

in ./tex/generic/pgf/systemlayer/pgfsys-dvips.def inside the TexLive folder.

Even then, it does not seem possible to end up with an eps file that works as expected (the bounding box seems broken in very mysterious ways)

Using Externalization

Option 2 is the externalization feature that's included in pgf itself.

\documentclass[a4paper,10pt]{article}
\usepackage{tikz}
\pgfrealjobname{levels_ext}

\begin{document}

\beginpgfgraphicnamed{levels}
\begin{tikzpicture}
    % ...
\end{tikzpicture}
\endpgfgraphicnamed

\end{document}

This method works equally well for pdflatex and just latex. However, I've seen it break for externalizing pictures from A0 posters. In this example, the file must be named levels_ext.tex. To obtain the file levels.dvi, we must compile the tex-file with the command

latex --jobname=levels levels_ext.tex

To go from the dvi file to an eps file, simply use dvips -o levels.eps levels.dvi. Do not give the -E flag to dvips: Even without it, the resulting postscript file will be in eps format (have a bounding box), but with it, the resulting file actually has bounding box problems.

If pdflatex instead of latex is used, a pdf file instead of a dvi file is generated.